Let the cost of a full unreserved ticket be \(F\) and the reservation charge per ticket be \(R\).
The cost of one full reserved ticket is the sum of the full unreserved ticket cost and the reservation charge:
$$ F + R = 525 \quad \cdots (A) $$
The cost of a half unreserved ticket is \( \frac{F}{2} \). The cost of one half reserved ticket is the sum of the half unreserved ticket cost and the reservation charge:
$$ \frac{F}{2} + R $$
The cost of one full reserved ticket and one half reserved ticket is given as Rupees 850:
$$ (F + R) + \left( \frac{F}{2} + R \right) = 850 $$
$$ F + R + \frac{F}{2} + R = 850 $$
$$ \frac{3F}{2} + 2R = 850 \quad \cdots (2) $$
From equation (A), we have \( F = 525 - R \). Substitute this into equation (2):
$$ \frac{3(525 - R)}{2} + 2R = 850 $$
$$ \frac{1575 - 3R}{2} + 2R = 850 $$
Multiply the entire equation by 2 to eliminate the fraction:
$$ 1575 - 3R + 4R = 1700 $$
$$ 1575 + R = 1700 $$
$$ R = 1700 - 1575 $$
$$ R = 125 $$
So, the reservation charge per ticket is Rupees 125.
We can also find the cost of the full unreserved ticket using equation (A):
$$ F + 125 = 525 $$
$$ F = 525 - 125 = 400 $$
The cost of a half unreserved ticket is \( \frac{400}{2} = 200 \).
The cost of one full reserved ticket \( = 400 + 125 = 525 \) (as given).
The cost of one half reserved ticket \( = 200 + 125 = 325 \).
The cost of one full and one half reserved ticket \( = 525 + 325 = 850 \) (as given).
Therefore, the reservation charge per ticket is Rupees 125.